New data shows that the four billion-year-old meteorite ALH84001, which fell on Earth decades ago, does not contain any signs of primordial life on Mars.
When scientists identified organic chemicals in an old Martian meteorite recovered in Antarctica in 1996, Science News stated that some experts felt the substances were strong proof of life on Mars. On the other hand, others suggested contamination by terrestrial life or non-biological origins.
Living creatures make organic molecules, but they can also come from nonbiological, abiotic processes. Various experts believe that abiotic organic molecules are crucial beginning material, despite many ideas explaining what started life.
Researchers detailed their study, "Organic Synthesis Associated With Serpentinization and Carbonation on Early Mars," in the journal Science.
VINCENNES BAY, ANTARTICA - JANUARY 11: Giant tabular icebergs are surrounded by ice floe drift in Vincennes Bay on January 11, 2008 in the Australian Antarctic Territory. Australia's CSIRO's atmospheric research unit has found the world is warming faster than predicted by the United Nations' top climate change body, with harmful emissions exceeding worst-case estimates.
Organic Material In Samples From Meteorite ALH84001 Made From Water?
According to the latest study, these molecules might have been produced by Martian geologic processes over billions of years. Originally, Andrew Steele and his colleagues at the Carnegie Institution for Science in Washington, D.C., checked how ancient Martian water influenced meteorite creation.
Steele's team employed modern technology, including sampling and analysis techniques, such as "imaging, isotopic analysis, and spectroscopy-to uncover the origin of organic compounds in the Allan Hills 84001 meteorite," according to a statement from the Carnegie Institution for Science (via Science Daily).
The researchers discovered samples of carbon-rich substances, indicating geochemical processes akin to Earth's water-rock interactions (serpentinization and carbonization). According to Steele, the data suggests that the organic material in the samples was most likely created by water.
Steele's team has found organic chemicals on previous Martian meteorites, but this is the first time a fragment from early Mars has been found.
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According to Steele, these nonbiological geological events provide a reservoir of organic carbon molecules from which life may have arisen. They offer a background signal that must be considered when looking for signs of past life on Mars.
Steele went on to say that the discoveries might help scientists learn more about early Earth and even Saturn's moon Enceladus.
However, two experts involved in the original study criticized the new findings, calling them "disappointing." Some experts stated they stood by their 1996 views in a shared email acquired by HuffPost.
Astromaterial experts at NASA's Johnson Space Center in Houston, Simon Clemett and Kathie Thomas-Keprta, observed that the data supplied progressively adds to our knowledge of the meteorite. However, Clemett and Thomas-Keprta pointed out that the interpretation isn't new or backed up by research.
They went on to say that unsupported speculation does little to answer the mystery surrounding the origin of biological materials in the meteorite.
Bringing Martian Samples To Earth Could Help Verify Life On Mars
According to Los Angeles Times, Steele believes that bringing samples to Earth for processing is the only way to determine whether Mars ever had or presently has microbial life. NASA's Perseverance Mars rover has already obtained six samples, which will be returned to Earth in about a decade; three dozen more are needed.
The meteorite crashed on an ice field in Antarctica thousands of years ago, after floating through space for millions of years. Allan Hills 84001 is the name given to the little gray-green piece after the hills where it was discovered.
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